The Federal Communications Commission’s plan to allow for Internet “fast lanes” has just run into another major roadblock. In a letter sent to the FCC, several tech heavyweights slammed its reported plans to let ISPs charge Internet companies more money in exchange for ensuring a faster delivery of their traffic. Among the many huge names to sign the letter were Google, Facebook, Amazon, Microsoft, Netflix, Dropbox and Yahoo.

“According to recent news reports, the Commission intends to propose rules that would enable phone and cable Internet service providers to discriminate both technically and financially against Internet companies and impose new tolls on them,” the companies wrote in the letter. “If these reports are correct, this represents a grave threat to the Internet. Instead of permitting individualized bargaining and discrimination, the Commission’s rules should protect users and Internet companies on both fixed and mobile platforms against blocking, discrimination and paid prioritization, and should make the market for Internet services more transparent.”